/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.streaming.util.graph;

import org.apache.flink.api.dag.Transformation;
import org.apache.flink.streaming.api.graph.StreamGraph;
import org.apache.flink.streaming.api.transformations.PhysicalTransformation;

/**
 * Utility class that contains helper methods to generating {@link org.apache.flink.streaming.api.graph.StreamGraph}.
 */
public final class StreamGraphUtils {

	/**
	 * Throw {@link IllegalStateException} if the {@link PhysicalTransformation}'s uid or hash is not
	 * set when auto generate uid is disabled.
	 *
	 * @param streamGraph The given graph that the transformation is added to
	 * @param transformation The transformation needed to validate
	 */
	public static void validateTransformationUid(
			StreamGraph streamGraph,
			Transformation<?> transformation) {
		if (!streamGraph.getExecutionConfig().hasAutoGeneratedUIDsEnabled()) {
			if (transformation instanceof PhysicalTransformation
					&& transformation.getUserProvidedNodeHash() == null
					&& transformation.getUid() == null) {
				throw new IllegalStateException("Auto generated UIDs have been disabled " +
						"but no UID or hash has been assigned to operator "
						+ transformation.getName());
			}
		}
	}

	/**
	 * Configure a stream node's buffer timeout according to the given transformation.
	 *
	 * @param streamGraph The StreamGraph the node belongs to
	 * @param nodeId The node's id
	 * @param transformation A given transformation
	 * @param defaultBufferTimeout The default buffer timeout value
	 */
	public static <T> void configureBufferTimeout(
			StreamGraph streamGraph,
			int nodeId,
			Transformation<T> transformation,
			long defaultBufferTimeout) {

		if (transformation.getBufferTimeout() >= 0) {
			streamGraph.setBufferTimeout(nodeId, transformation.getBufferTimeout());
		} else {
			streamGraph.setBufferTimeout(nodeId, defaultBufferTimeout);
		}
	}
}
